RoutedEvents 组合框未触发

Question

您好，请好心人帮忙。我有两个用户控件。一个带有文本框，另一个带有组合框。修改组合和文本框后，主窗口将执行计算例程。 文本框版本有效，组合框无效。我能看到的唯一区别是 文本框使用 TextChangedEventArgs 然而 组合框使用 System.EventArgs

有什么想法吗？ 谢谢

// UserControl - with TextBox

public event RoutedEventHandler ucTextChanged;

        private void OnTextChanged(object sender, RoutedEventArgs e)
        {
            if (ucTextChanged != null)
            {
                ucTextChanged(this, new RoutedEventArgs());
            }
        }

       private void txtValue_TextChanged(object sender, TextChangedEventArgs e)
        {
            OnTextChanged(sender, e);
        }

// UserControl - ComboBox

      public event RoutedEventHandler ucComboChanged;


        private void OnComboChanged(object sender, RoutedEventArgs e)
        {
            if (ucComboChanged != null)
            {
                ucComboChanged(this, new RoutedEventArgs());
            }
        }

      private void ucCombo_DropDownClosed(object sender, System.EventArgs e)
        {
        OnComboChanged(sender, e);      
        }

Answer 1

尝试查看 ComboBox 的事件 SelectionChanged (https://docs.microsoft.com/en-us/dotnet/api/system.windows.controls.combobox.onselectionchanged)

XAML：

<ComboBox SelectionChanged="ucCombo_SelectionChanged"></ComboBox>

C#：

    private void ucCombo_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        // your code here...
        OnComboChanged(sender, e);
    }